1. a person or thing that convinces someone; something that serves as proof or persuasive evidence
2. a decisive or conclusive argument or fact that removes doubt
Usage: informal

Examples

• The test results were a convincer that the new treatment actually works.
• Seeing the before-and-after photos was the convincer I needed to buy the product.
• His calm explanation under pressure was a convincer of his leadership ability.
• The financial data served as a convincer for the board to approve the merger.
• That one goal in the final minute was the convincer that sealed the team's victory.
• Her years of experience were a convincer that she deserved the promotion.